Waterproof wood filler

I usually use Timbermate wood filler for a lot of projects and I used it to fill some screw holes that are out doors. After some recent rains I noticed there were all these lumps forming under the paint. So I scraped the paint off and the Timbermate had turned into a mushy mess. Any recommendations for a water proof wood filler? Any oil based wood filler recommendations? Epoxy? Bondo? Anything else? I want something easy to work with and sands nicely.

-- Wood Menehune, Honolulu

1 reply so far

Bondo works well for painted items, as does epoxy fillers like MarineTex.

I use PL fi:x professional wood filler (available here at Lowe’s) and have had good luck with it (it is acetone thinned, not water-based). Easy to apply, fast drying and easy to sand. (less messy and easier to work with than bondo or marine tex). I have not tried it outdoors in full weather, but the can says that “exterior patches must be painted”, which leads me to believe it would work.